Chapter 23 WAN Optimization, Web Cache, Explicit Proxy, and WCCP : Configuring WAN optimization : WAN optimization and user and device identity policies, load balancing and traffic shaping : Traffic shaping
  
Traffic shaping
Traffic shaping works for WAN optimization traffic that is not in a WAN optimization tunnel. So traffic accepted by a WAN optimization security policy on a client-side FortiGate unit can be shaped on ingress. However, when the traffic enters the WAN optimization tunnel, traffic shaping is not applied.
In manual mode:
Traffic shaping works as expected on the client-side FortiGate unit.
Traffic shaping cannot be applied to traffic on the server-side FortiGate unit.
In active-passive mode:
Traffic shaping works as expected on the client-side FortiGate unit.
If transparent mode is enabled in the WAN optimization profile, traffic shaping also works as expected on the server-side FortiGate unit.
If transparent mode is not enabled, traffic shaping works partially on the server-side FortiGate unit.